.hello {
    width: 100vw;
    height: 100vh;
    background-color: #5e5e5e;
    position: relative;
    text-align: center;
    .logo {
        width: 444px;
        height: 268px;
    }
    .hello-title {
        color: #fff;
        margin: 20px 0;
        font-size: 50px;
        animation: tada 2s ease-in-out infinite;
    }
    .username {
        margin: 20px 0;
    }
    .btn-start {
        height: 50px;
        font-size: 20px;
    }
    .hello-content {
        top: 0;
        left: 50%;
        position: absolute;
        transform: translateX(-50%);
    }
}
@keyframes tada {
  from {
    transform: scale3d(1, 1, 1);
  }

  10%, 20% {
    transform: scale3d(.9, .9, .9) rotate3d(0, 0, 1, -3deg);
  }

  30%, 50%, 70%, 90% {
    transform: scale3d(1.1, 1.1, 1.1) rotate3d(0, 0, 1, 3deg);
  }

  40%, 60%, 80% {
    transform: scale3d(1.1, 1.1, 1.1) rotate3d(0, 0, 1, -3deg);
  }

  to {
    transform: scale3d(1, 1, 1);
  }
}
